Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1349,8 +1349,6 @@
   "%0 cannot be defined in a type alias template">;
 def err_type_defined_in_condition : Error<
   "%0 cannot be defined in a condition">;
-def err_type_defined_in_enum : Error<
-  "%0 cannot be defined in an enumeration">;
 
 def note_pure_virtual_function : Note<
   "unimplemented pure virtual method %0 in %1">;
Index: clang/lib/Parse/ParseExpr.cpp
===================================================================
--- clang/lib/Parse/ParseExpr.cpp
+++ clang/lib/Parse/ParseExpr.cpp
@@ -2373,7 +2373,7 @@
 
     // Parse the type declarator.
     DeclSpec DS(AttrFactory);
-    ParseSpecifierQualifierList(DS);
+    ParseSpecifierQualifierList(DS, AS_none, DSC_type_specifier);
     Declarator DeclaratorInfo(DS, Declarator::TypeNameContext);
     ParseDeclarator(DeclaratorInfo);
     
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -14012,13 +14012,6 @@
     Invalid = true;
   }
 
-  if (!Invalid && getLangOpts().CPlusPlus && TUK == TUK_Definition &&
-      DC->getDeclKind() == Decl::Enum) {
-    Diag(New->getLocation(), diag::err_type_defined_in_enum)
-      << Context.getTagDeclType(New);
-    Invalid = true;
-  }
-
   // Maybe add qualifier info.
   if (SS.isNotEmpty()) {
     if (SS.isSet()) {
Index: clang/test/CXX/drs/dr5xx.cpp
===================================================================
--- clang/test/CXX/drs/dr5xx.cpp
+++ clang/test/CXX/drs/dr5xx.cpp
@@ -424,7 +424,7 @@
   while (const n = 0) {} // expected-error {{requires a type specifier}}
   for (const n = 0; // expected-error {{requires a type specifier}}
        const m = 0; ) {} // expected-error {{requires a type specifier}}
-  sizeof(const); // expected-error {{requires a type specifier}}
+  sizeof(const); // expected-error {{expected a type}}
   struct S {
     const n; // expected-error {{requires a type specifier}}
     operator const(); // expected-error {{expected a type}}
Index: clang/test/SemaCXX/enum.cpp
===================================================================
--- clang/test/SemaCXX/enum.cpp
+++ clang/test/SemaCXX/enum.cpp
@@ -114,7 +114,7 @@
 // PR28903
 struct PR28903 {
   enum {
-    PR28903_A = (enum { // expected-error-re {{'PR28903::(anonymous enum at {{.*}})' cannot be defined in an enumeration}}
+    PR28903_A = (enum { // expected-error-re {{'PR28903::(anonymous enum at {{.*}})' cannot be defined in a type specifier}}
       PR28903_B,
       PR28903_C = PR28903_B
     })